Supplementary Material for: Differences in Serum Alkaline Phosphatase Levels in Infants with Spontaneous Intestinal Perforation versus Necrotizing Enterocolitis with Perforation

<b><i>Introduction:</i></b> Data on laboratory markers of spontaneous intestinal perforation (SIP) and necrotizing enterocolitis (NEC) remain sparse. <b><i>Objective:</i></b> To compare serum alkaline phosphatase levels in infants with bowel perforation secondary to SIP versus surgical NEC, and then investigate the possible role of serum alkaline phosphatase in differentiating infants with these conditions. <b><i>Methods:</i></b> A retrospective case-control study of infants admitted with bowel perforation from 2005 to 2015. Demographic and prenatal data, postnatal exposures, and clinical, laboratory, and radiographic findings were extracted from inpatient medical records and analyzed using regression analysis. <b><i>Results:</i></b> Of 114 outborn infants included, 48 infants had SIP (cases) and 66 had NEC (controls). Upon admission from the referring hospital, the serum alkaline phosphatase level was significantly higher in infants with SIP, i.e., a median value of 782 versus<i></i>236 U/L in NEC patients (<i>p</i> &lt; 0.0001), with an adjusted odds ratio (OR) of 4.3 (<i>p</i> &lt; 0.05) when the level was &gt;500 U/L in multivariate regression model. Infants with SIP had significantly younger gestational age, presented earlier in life, primarily with pneumoperitoneum, and had greater exposure to steroids and indomethacin compared to infants with NEC. Alkaline phosphatase levels decreased rapidly in infants with SIP following admission. <b><i>Conclusion:</i></b> A transient increase in serum alkaline phosphatase level is independently associated with SIP when compared to NEC. Studies to confirm the role of alkaline phosphatase in the diagnosis of SIP are necessary and have potentially significant clinical and prognostic implications.

**引言**：目前关于自发性肠穿孔（spontaneous intestinal perforation, SIP）与坏死性小肠结肠炎（necrotizing enterocolitis, NEC）的实验室标志物相关数据仍较为匮乏。
**目的**：对比继发于自发性肠穿孔（SIP）与外科坏死性小肠结肠炎（NEC）的肠穿孔患儿的血清碱性磷酸酶（serum alkaline phosphatase）水平，并探讨血清碱性磷酸酶在鉴别这两类患儿中的潜在作用。
**方法**：本研究为回顾性病例对照研究，纳入2005年至2015年期间因肠穿孔入院的院外出生转诊患儿。研究人员从住院病历中提取患儿的人口统计学资料、产前数据、产后暴露情况、临床特征、实验室检查结果及影像学表现，并采用回归分析法进行数据分析。
**结果**：纳入的114名患儿中，48名确诊为SIP（病例组），66名确诊为NEC（对照组）。转诊入院时，SIP患儿的血清碱性磷酸酶水平显著更高，中位数为782 U/L，而NEC患儿为236 U/L（p<0.0001）；在多变量回归模型中，当血清碱性磷酸酶水平>500 U/L时，校正后的优势比（odds ratio, OR）为4.3（p<0.05）。与NEC患儿相比，SIP患儿的胎龄显著更小，发病年龄更早，主要表现为气腹，且更多暴露于类固醇与吲哚美辛。入院后，SIP患儿的血清碱性磷酸酶水平快速下降。
**结论**：与NEC相比，血清碱性磷酸酶水平的一过性升高与SIP独立相关。未来需开展相关研究以验证碱性磷酸酶在SIP诊断中的价值，该方向具有重要的临床与预后意义。